On Tue, Feb 23 2016, Lars Magne Ingebrigtsen wrote:

[...]

> This is definitely a bug, and it comes from here:

> (cl-defmethod gnus-icalendar-event:org-timestamp ((event gnus-icalendar-event))
>   "Build `org-mode' timestamp from EVENT start/end dates and recurrence info."
>   (let* ((start (gnus-icalendar-event:start-time event))
>          (end (gnus-icalendar-event:end-time event))
>          (start-date (format-time-string "%Y-%m-%d %a" start))

> %a is the locale's day name, and that's not something `date-to-time' can
> parse.  But I'm not familiar with gnus-icalendar, so I'm not sure what
> the right fix is here.

> Jan, is the week day supposed to be in these date strings at all?

How about this? It's a patch against the emacs-25 branch, I was not able
to connect to the gnus git.